Cometic Head Gaskets are specially built for forced induction, high compression, or nitrous applications. It features a thicker shim around the cylinder walls to increase seal. The outer layers of the gasket are embossed and coated on both sides with a flouroelastomer rubber based material (Viton) designed to meet the demands of a variety of harsh sealing environments, load conditions and surface finishes. Bore of 3.595". Made to order by Cometic at ships in approx. 10 business days.